The present invention relates to a system and method of making paperboard and paperboard corrugation that negates the steps of winding rolls of containerboard on machine reels of separate paper machines, subsequent rewinding and slitting of paperboard and unwinding rolls of containerboard on separate corrugators.
In the prior art, linerboard is made on a single machine where the product is wound into a roll. Corrugating medium is also made on a separate machine and then wound on a roll. Normally corrugating medium and linerboard are made on different machines because of different characteristics of the two boards. The rolls of containerboard are then, subsequently slit and rewound to fit the corrugator""s width, which is typically narrower than the board machine. The rolls are subsequently brought to a separate facility where the corrugator is located where the rolls are placed on unwind stands and unwound to be made into corrugated sheet. With all of the costs involved in transportation, and winding and unwinding of rolls, and keeping inventory of the rolls (at both the corrugator and paperboard manufacturing facilities) this becomes a very inefficient process.
The present invention involves a method of paperboard corrugation that produces at least one continuous web of containerboard at a papermaking segment of the process that continuously feeds the containerboard web or webs from the dry-end of the papermaking segments into another segment of the process that converts the webs into corrugation board (the corrugation segment). Containerboard is defined as paperboard used to make corrugated containers, corrugating medium plus linerboard. This process negates the steps of winding rolls of paper on paper machine reels, rewinding and slitting paper on rewinders, and unwinding of rolls of paperboard on conventional corrugators. While only a single or two webs of containerboard can be produced at the papermaking segments (thereby requiring the remaining web or webs needed for producing the corrugated board to be fed into the corrugation segment by unwinding rolls of containerboard with traditional roll unwinders), it is considered more advantageous to feed all three webs from papermaking segments into the corrugation segment.
When all three webs are continuously fed from papermaking segments, all the necessary containerboard webs are be produced in a single process for combining the webs into single wall corrugated board, which represents approximately 90% of the corrugated board market. Additional webs could be unwound for making double or triple wall products (the remaining 10% of the market).
An object of the invention is to eliminate winding and unwinding of webs. This eliminates a great deal of capital, manning requirements, transportation costs, energy and plant floor space requirements.
A further object of the invention is to eliminate or reduce web pre-heating equipment found on prior art corrugators. This equipment may be unnecessary as the webs are of sufficient temperature from the paper forming segments to effectively perform the corrugation process without preheating.
The present invention relates to a system for producing corrugated board comprising; an inside linerboard segment, an outside liner board segment, and a corrugating medium segment all being formed continuously or in one process. The three segments can be in many different configurations. The system can comprise all three segments in one line. It is a further object of the present invention for the corrugating medium segment and inside linerboard segment to be placed back to back. It is an object of the present invention to place two of the segments back to back and the third segment placed above or below one of the two back to back segments. It is a further object of the invention for the segments to be oriented in a stacked fashion. It is a further object of the invention to have any one of the segments being formed from pulp and the other two segments unwound from a roll during the same process to manufacture the corrugated paperboard. It is an object of the present invention for the corrugating medium to be produced from pulp and the inside liner board segment and the outside linerboard segment to be delivered via rolls.
It is an object of the present invention to have each of the segments comprise; a headbox, paper forming section, press section and a dryer section. It is an object of the present invention for each of the segments to have an air laid fourdrinier. It is a further object of the invention for the system to comprise a print side linerboard forming segment having a calendar section to add smoothness.
It is an object of the present invention to provide a method of paperboard corrugation comprising; delivering pulp to an inside linerboard segment, corrugating medium segment and an outside linerboard segment. The pulp is then converted into three separate containerboard webs. The corrugating medium web is then fluted. The inside linerboard web is bonded to the corrugating medium web forming a single face corrugated web. The single corrugated web is joined to the outside linerboard web forming a single wall corrugated board. It is an object of the present invention to add smoothness to the outside linerboard web prior to joining with the single face web. It is a further object of the present invention to slit and cut the single wall corrugated board into corrugated sheets. It is an object of the present invention to move broke from the paperboard corrugation system to a pulper for repulping to create fibers to re-enter the system of the present invention.
The present invention can be accomplished using conventional equipment, i.e. fourdrinier or cylinder forming equipment or using non-conventional equipment.